gbsv MC2¶

Day 1 - Auto-Correlation¶

Overarching Task: Choose a country and theme all the MC tasks to this county. The use cases, problem statements, signals and images should be related to your country of choice. It can be the same country as in MC1, but you may also choose a different one.

Day 1 Task Passend zu deinem Land: Definiere einen Anwendungsfall, um zu erkennen, ob ein 1D Signal wiederkehrende Muster enthält. Suche ein passendes 1D Signal (Audio, Zeitreihe, Vitalparameter, ...), welches wiederkehrende Muster enthält, um in den Folgetagen Auto-Korrelation anzuwenden.

In [1]:
import time
start_time = time.time()
import cv2 as cv
import librosa
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import sounddevice as sd

from ipywidgets import interact, widgets
from matplotlib import pyplot as plt
from matplotlib.widgets import Slider, Button, TextBox
from scipy.io.wavfile import write
In [2]:
audio, sampling_rate = librosa.load("sound/bell.wav")
print(f"{audio=}")
print(f"{audio.dtype=}")
print(f"{audio.shape=}")
print(f"{np.max(audio)=}")
print(f"{np.min(audio)=}")

from IPython.display import Markdown, Audio

display(Markdown(f"**ring the Bell**"))
display(Audio(audio, rate=sampling_rate))

audio=array([2.6749703e-35, 8.3550063e-35, 1.1725352e-34, ..., 6.8832678e-04,
       7.8442483e-04, 0.0000000e+00], dtype=float32)
audio.dtype=dtype('float32')
audio.shape=(1641260,)
np.max(audio)=np.float32(0.86444175)
np.min(audio)=np.float32(-0.8645316)

ring the Bell

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The chosen use case is to estimate the weight/size of a Swiss cowbell based on its frequency characteristics using auto-correlation. Cowbells produce distinct resonant frequencies determined by their size, material, and weight. Identifying recurring patterns in their acoustic signal can help derive these physical properties. i chose this sound because cowbells are an iconic symbol of Swiss craftsmanship and tradition, and we can always hear them on our hiking trips on weekends. The objective of this experiment is to demonstrate whether auto-correlation can reliably detect these recurring patterns and link them to the bell’s weight. The chosen signal is a recording of a Swiss cowbell.